1 /*
  2  * Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  4  *
  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
 16  * 2 along with this work; if not, write to the Free Software Foundation,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
 21  * questions.
 22  *
 23  */
 24 
 25 #ifndef SHARE_GC_SHARED_MODREFBARRIERSET_HPP
 26 #define SHARE_GC_SHARED_MODREFBARRIERSET_HPP
 27 
 28 #include "gc/shared/barrierSet.hpp"
 29 #include "memory/memRegion.hpp"
 30 
 31 class Klass;
 32 
 33 class ModRefBarrierSet: public BarrierSet {
 34 protected:
 35   ModRefBarrierSet(BarrierSetAssembler* barrier_set_assembler,
 36                    BarrierSetC1* barrier_set_c1,
 37                    BarrierSetC2* barrier_set_c2,
 38                    const BarrierSet::FakeRtti& fake_rtti)
 39     : BarrierSet(barrier_set_assembler,
 40                  barrier_set_c1,
 41                  barrier_set_c2,
 42                  NULL /* barrier_set_nmethod */,
 43                  fake_rtti.add_tag(BarrierSet::ModRef)) { }
 44   ~ModRefBarrierSet() { }
 45 
 46 public:
 47   template <DecoratorSet decorators, typename T>
 48   inline void write_ref_field_pre(T* addr) {}
 49 
 50   template <DecoratorSet decorators, typename T>
 51   inline void write_ref_field_post(T *addr, oop new_value) {}
 52 
 53   // Causes all refs in "mr" to be assumed to be modified.
 54   virtual void invalidate(MemRegion mr) = 0;
 55   virtual void write_region(MemRegion mr) = 0;
 56 
 57   // Operations on arrays, or general regions (e.g., for "clone") may be
 58   // optimized by some barriers.
 59 
 60   // Below length is the # array elements being written
 61   virtual void write_ref_array_pre(oop* dst, size_t length,
 62                                    bool dest_uninitialized = false) {}
 63   virtual void write_ref_array_pre(narrowOop* dst, size_t length,
 64                                    bool dest_uninitialized = false) {}
 65   // Below count is the # array elements being written, starting
 66   // at the address "start", which may not necessarily be HeapWord-aligned
 67   inline void write_ref_array(HeapWord* start, size_t count);
 68 
 69  protected:
 70   virtual void write_ref_array_work(MemRegion mr) = 0;
 71  public:
 72   // The ModRef abstraction introduces pre and post barriers
 73   template <DecoratorSet decorators, typename BarrierSetT>
 74   class AccessBarrier: public BarrierSet::AccessBarrier<decorators, BarrierSetT> {
 75     typedef BarrierSet::AccessBarrier<decorators, BarrierSetT> Raw;
 76 
 77   public:
 78     template <typename T>
 79     static void oop_store_in_heap(T* addr, oop value);
 80     template <typename T>
 81     static oop oop_atomic_cmpxchg_in_heap(T* addr, oop compare_value, oop new_value);
 82     template <typename T>
 83     static oop oop_atomic_xchg_in_heap(T* addr, oop new_value);
 84 
 85     template <typename T>
 86     static void oop_arraycopy_in_heap(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw,
 87                                       arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw,
 88                                       size_t length);
 89   private:
 90     // Failing checkcast or check null during copy, still needs barrier
 91     template <typename T>
 92     static inline void oop_arraycopy_partial_barrier(BarrierSetT *bs, T* dst_raw, T* p);
 93   public:
 94     static void clone_in_heap(oop src, oop dst, size_t size);
 95 
 96     static void oop_store_in_heap_at(oop base, ptrdiff_t offset, oop value) {
 97       oop_store_in_heap(AccessInternal::oop_field_addr<decorators>(base, offset), value);
 98     }
 99 
100     static oop oop_atomic_xchg_in_heap_at(oop base, ptrdiff_t offset, oop new_value) {
101       return oop_atomic_xchg_in_heap(AccessInternal::oop_field_addr<decorators>(base, offset), new_value);
102     }
103 
104     static oop oop_atomic_cmpxchg_in_heap_at(oop base, ptrdiff_t offset, oop compare_value, oop new_value) {
105       return oop_atomic_cmpxchg_in_heap(AccessInternal::oop_field_addr<decorators>(base, offset), compare_value, new_value);
106     }
107 
108     static void value_copy_in_heap(void* src, void* dst, InlineKlass* md);
109   };
110 };
111 
112 template<>
113 struct BarrierSet::GetName<ModRefBarrierSet> {
114   static const BarrierSet::Name value = BarrierSet::ModRef;
115 };
116 
117 #endif // SHARE_GC_SHARED_MODREFBARRIERSET_HPP